In the field of airborne equipment, for example, notably equipment of the optical bench or suspended radar type, the vibration environment is generated by vibrations transmitted by the carrier airplane and the aerodynamic turbulence on the exterior structure of the equipment. The current solution for vibration isolation of the structure of airborne equipment uses passive dampers of elastomer material. FIGS. 1A and 1B illustrate the diagram of a load 10 suspended in a rigid support 11 using a mechanical connection comprising two suspension elements 12 of the elastomer damper type and a line 13 which shows at a logarithmic scale the rate of the modulus of the transfer function which is associated with this connection in accordance with the excitation frequency f. The line 13 is obtained, for example, by taking the ratio between the acceleration amplitudes N2/N1 of the load (N2) and the support (N1), respectively, when it is subjected to a sinusoidal excitation of specific acceleration amplitude A and frequency amplitude f. The line 13 shows that, at low frequency, the modulus of the transfer function is equal to 1, that is to say that N2 and N1 have a similar movement, then, for a specific frequency f0, called the resonance frequency, the transfer function has a maximum value Q, called an overload value. The resonance frequency value is linked substantially to the rigidity of the connection and the value of the overload is linked to the damping. A connection with little damping has a high overload value and the value of the resonance frequency is even smaller when the rigidity is low (at a specific load mass). Above a frequency value fc called the cut-off frequency, a filtering of the vibrations can be seen (transfer function less than 1).
The main disadvantages encountered nowadays with this type of connection which uses elastomer dampers include in particular significant variations in performance levels (rigidity, damping) in accordance with the temperature and vibration amplitudes and frequencies resulting from the non-linearities of the elastomer material, a dispersion of the rigidities of the dampers from one production to another, bringing about significant residual rotations of the suspended equipment, and a possibility of creep of the suspension element after application of thermal cycles or vibration or static acceleration bringing about a modification of the relative position of the load relative to the support. These disadvantages are amplified by the anisotropy of the rigidity of the suspension element constituted in this manner.